Best Brass Old Series Signature Mouthpiece, Horn From the former NHK Symphony Orchestra, Tetsuo Higuchi Symphonic Model. It has an inner diameter of 18mm, but the rim is thin, so it doesn't feel that big. The throat is also narrow, so it doesn't take a large amount of air, making it a well-balanced mouthpiece. I am selling it because I am currently using something similar. It is made by Best Brass, but it is a product from before the current model had the throat groove. The cup is not mirror-finished, but it may have a similar effect. The blowing feel is, in a good way, normal. I don't feel any special resistance. I often used it with an Alexander 103, but when playing forte, I felt that the peak came (broke) earlier compared to other mouthpieces of the same size. It may be recommended for those who are looking for a brighter tone rather than a soft tone. Feel free to ask for additional photos or price negotiations. Manufacturer's Description A symphony model with a very large inner rim diameter and a gently expanding, large-capacity cup. The comfortable rim and the rim with a clear bite have both flexibility and good pronunciation. Due to the medium and slightly long throat and the slightly narrow backbore for the large-capacity cup, a good balance is obtained. It has stable breath control and a firm embouchure, and is suitable for players who prefer large-diameter mouthpieces. A well-balanced mouthpiece that can be used with instruments from narrow bells to wide bells. Price: Production discontinued Specifications Inner rim diameter: 18.042 Bite: Sharp Apex diameter: 21.044 Cup depth: Normal Outer diameter: 24.9 Cup shape: Slightly U Width: 3.429 Throat: 4.1 Apex balance: 44% Backbore: HR-MS Rim shape: Round Compatible with other companies: Schilke 31B